This CCRU is jointly sponsored by the Fred Hutchinson Cancer Research Center and the University of Washington School of Public Health and Community Medicine. The Seattle and Puget Sound area under Surveillance within the SEER Program is its research reference population. Its major initial research focus is prevention, particularly primary prevention intervention trials. Its secondary objective is the measurement of improved patient management as a consequence of community intervention, like the NCI CCOP program. Long-term objectives include population-based studies of the effectiveness of proven interventions and expansion of the reference population, populations available for experimental studies, and the development of improved cancer control research strategies.